Connecting pin



March 24, 1931.

A E. FREEMAN CONNECTING PIN Filed Dec. 29, 1928 INVENTOR /ZEFl'veen/em v ATTORNEY locking mechanism for such pin through the Patented Mara 24, 1931 ALBERT n. rnnnivrnn, or EAST onnnenjnnwzrnnsnv, .assicnon-jqro A ERIoAn 'rnLEr' vrnonn nnn frnLnennrnioo vrrnnY, A CORPORATION on N W YORK I i r o mwmdf m Application fiied ne emb'er'ae,1928.1ser al no. 329,213; 7

This inventionrelates to pins, and more vparticularly to-connecting pins adapted to be "inserted throughcoinciding openings in mechanical elements, such as'telescopic memfibers, to maintain them in joined relation.

' In the connection of mechanicalelem'ents,

- for instance "telescopic-members of pole derricksor the like, it is customary to adjustth'e members to a desired length, and then insert v19 a bolt through 1 coinciding openings in the members to maintain them in fixed relationl After thebolt is place, a nut isappliedto the-extended threaded end*of the-bolt in a well-known manner. If the openingsfin. the

T members do not'exactly agree in alignment,

difiiculty is experienced in in'sertingthe bolt therethrough, and after the bolt is in posia tion, an additional operation of applying a nut toits-extended threaded end is required. Accordingly, itis one of the objects of this invention to provide a connecting pin for members ofthe character referred to which may be, readily attached to' and detached from such members. p

Another object consists in the provision of medium of which the pin is prevented from becoming-accidentally. displaced after it is in position. 1

A further'object consists inthe provision of a connecting pin which is rugged, simple and comparatively inexpensive.

These and further objects will be apparent 'from'the following description, when consideredin connection with the accompanying drawing, in which one embodiment of the invention is illustrated.

Referring to the drawing, Figure 1 is a side elevation, partly in section, of the improved pin; Fig. 2 is a right end'view thereof, and Fig. 3 is an exploded View of the locking mechanism for the pin.

The improved connecting pin which'may be composed of suitable metal, such as steel or the like, consists of a cylindrical shank 5vwhich is provided with a semi-spherical head 6. A circular aperture 7 extends from one end of the shank 5 into the approximate center thereof and lieseccentric to the longi-v tudinal axis of the shank.

versely throughthe improved'conn ec ting pin and through a slot 13 provided between bifur- This locking mechanism'comprises a cylindri- 3 cal shank '8 having an integral head portion 9. Whichlies contiguous the end of the pin.

Thehead 9 is'of substantiallyfrusto-conical sh'ape'being somewhat bluntat its outer end and having tapered side portions which con; .nect with its circular inner end. The head Elvis positionedineccentric relation with respect to theshank 8 of the locking mecha j nism,'-and its inner circular face is practically I the samediameter asthatfof. the "shank 5 0i the connecting pin. The head 9' is adapted to be rotated, and is shown in full lines in -'Figs. 1 and 2-in its normal position in align-j mentwith :the shank 5, while as shown in dotted lines's'inthese figures itis in its oper atedflockedpositionand lies in eccentric re lation toj theshank v shape d" slot "is provide'dat thee'ndof the cylindrical shank'8,

and'a similarly shaped'point' isprovide'd on a detent 10..which'registers insaid slot. 5 The pointon the deten'tflO, is preferably dull to prevent excess friction between the detent and shank 8 duringtherOtatiOn of the latter'mem ber-tobepresently described.

f A spiral-spring, 11,positioned'fat the inner end of the:a perture7, engages anend of' the detent. 1O and: maintains constant pressure thereo'ns. The detent-is prevented-'from'rotat 1 ing by means'of. a pinlZ which passes transcated 'portionsof thedetent 10. A second pin '14 also-passes transversely throughthe improved device and is seated in-aicircumferential'groove 15provided in the shank 8'.- The pin 14 prevents longitudinal? movement of the locking mechanismincluding the spring, detent, shank and head: members so that they can notrbecome displaced from the connect ing-pin; The pin 14,-however, permits the rotation ofzthe shankl and its head member 9. .ThetaperedEside-portions' maybe provided with parallel grooves16 which serve to form a grip byiwh-ich the head 9 may be grasped, to facilitate-f its rotation. These grooves; may have anaaperture l7 extending between them, through which a suitable pin may be inserted to turn the head in case said head may adhere to the shank 5 by reason of rust.

The head member may be readily entered through the openings of the members which it is to connect due to its tapered or frustoconical shape. The openings do not need to exactly coincide, as the tapered head when inserted through these openings will force them into'alignment. r v

The connecting pin may be forced or hammered into place without injuring its locking mechanism, and it may also be removed by applying hammer blows to the tapered head without injuring the locking mecha- The :tapered head member which is normally in alignment with the main shank of the pin may be turned 180? in either direction to, moveit into a locked position The head in its locked position will lie in eccen tric relation to the longitudinal axis of the pin. In this position the'improved pin will be prevented from becoming withdrawn from. the members which 'it'holds in joined rela tion. To releasethe head member from its 1 locked position, it needonly be rotated 180 to cause it to assume its normal position. The

locking and unlocking of the pin is .quickly accomplished without the use of tools. In the tiguous faces of said head member and said cylindrical member being of similar cross-section and constantly engaging each other, said head member in normal position being in alinement with the cylindrical member and in locked position being eccentric thereto, and means carried by the cylindrical member for preventing longitudinal movement of the head member from the cylindrical member.

3. A- connecting pin comprising a cylindrical member adapted to be'inserted through apertured members to hold them in joined relation, a head member mounted on one end thereof and adapted to-be rotated from a normal alined position tothe cylindrical memrotation of the head from its'normal position to its locked position, or vice'versa, the shank connected: with the head-is caused to rotate, and the slot in the shank registers with the point of the detent in either position. The spiral spring which engages the detent causes it to maintain constant pressure on the shank member and its integral head member. It will be apparent that accidental unlockinglof the head member is prevented because said 7 head member requires a definite turning force.

The locking mechanism is non-detachable from the improved connecting pin because of the transverse pin which passes therethrough and engages the circumferential groove in the shank of the head member. Accordingly,

the parts constituting the can not becomelost.

What'is claimed is 1. 'A connecting pin having a cylindrical member,-locking mechanism mounted in eccentric relation to the axis of the cylindrical member, a tapered head member for the looking mechanism rotatably mounted on the cy lindrical member, said headmember and said cylindrical member having contiguous surfaces of similar cross-section, and means carlocking mechanism ried by the cylindrical member for preventing longitudinal movement of :the locking mechanism and the head'member from the cylindrical member. 1 a

2. A connecting pin having a cylindrical member, a tapered headmember rotatably. mounted on the cylindricalmember, the con- 

